Heraclius

Heraclius (575-11 February 641) was the Emperor of the Byzantine Empire from 610 to 641, succeeding Phocas of Byzantium and preceding Constantine III of Byzantium.

Biography
Son a Byzantine general, in 608, Heraclius began a revolt in north Africa against the tyrannous Emperor Phocas. Two years later, he executed Phocas and took the throne. As emperor, Heraclius began important reforms, which included creating a class of Byzantine soldier-farmers who held land in return for military service. However, Heraclius struggled to cope with attacks from Avars and Slavs in the Balkans and the Persian Sasanian Chosroes II in the East. When the Sasanians invaded Anatolia, threatening Constantinople, Heraclius at first thought of abandoning the capital and withdrawing to Carthage. Instead, in 622, he began to fight back. Of imposing physique and great personal courage, he led his armies on successful campaigns in Anatolia and Armenia. Beating off a siege of Constantinople in 626, the next year he struck deep into Mesopotamia. In December, the Byzantine and Sasanian armies clashed at Nineveh. The battle was a triumph for Heraclius, who allegedly killed the Sasanian commander, Rhahzadh, with a single blow of his sword. Chosroes was overthrown by his own people and his successor sued for peace.

Unfortunately for Heraclius, at this pinnacle of his success, Arab armies inspired by the new religion of Islam posed a sudden threat. No longer leading troops in the field, Heraclius sent armies to resist the Arabs in vain, suffering an especially severe defeat at Yarmuk in 636. By the time of his death in 641, the Byzantines had lost Egypt and the Levant to the rising Arab tide.